MONTECITO, Calif. -- Search-and-rescue dogs are leading the efforts to find the missing in the wake of deadly mudslides that swallowed neighborhoods in Southern California. The challenges are mounting for first responders.

More than 36 hours after the floods began, crews were poking through mud with sticks looking for anyone who might be trapped.

"You kind of do what you do when there's an avalanche," Battalion Chief Neil Berryman of the San Luis Obispo Fire Department told CBS News. "You poke and if you feel something different you try to figure out what it is."

More than 100 people have been rescued, many from rooftops by helicopter.

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CBS News

Already scorched by the massive Thomas Fire in December, hillsides in Montecito collapsed in less than 15 minutes. Marco Ferrell had just gone outside his parents' home when he saw the mud and debris coming. He yelled to warn others and shot video on his phone.

"I basically ran for my life, I ran as fast as I could, made it back to my house in about 30 seconds of the front of the flash flood hitting," Ferrell to CBS News.

Marco Ferrell
CBS News

Seconds later a boulder crashed through his kitchen door.

"We had waist deep mud raging through my house, every inch of my house," he said.

Major roads were swamped, trapping many in their homes. Oprah Winfrey posted a video walking through mud at her Montecito estate.

Voluntary evacuation orders were issued, but only 15 percent of the residents left. Many who got caught in the mudslides had just evacuated in December during the wildfires.

Ferrell was not surprised about how many people died.

"This town has evacuation fatigue. A lot of people were complacent," he said.